2017:764 - OLD KILMAINHAM: New Children’s Hospital at St James Hospital Campus, Mount Brown, Dublin

The archaeological excavation of 44 test trenches covering an area of 215m2 was required in advance of the development of the New Children’s Hospital, Mount Brown. The test excavations were carried out on a phased basis between March and December 2017 as each area became available following demolition of extant buildings.

Forty-three trenches (Trenches 50–92) were located to target specific features, including buildings, a water reservoir, water channels and a ropewalk, depicted on the historical OSI maps of 1864, 1887 and 1907. An additional trench (Trench 30) remaining from the 2016 phase of test trenching by Thaddeus Breen, Shanarc Archaeology, under licence number 16E0408, was also excavated.

Nothing of archaeological significance was uncovered in 29 of the 44 trenches (Trenches 30, 50–55, 60, 62–67, 74–76, 78–79, 82–85 and 87–92). In the remaining 15 trenches, exposed 19th- and early 20th-century features comprised a watercourse, a drainage ditch, a possible field boundary ditch, 15 post-holes, as well as brick and stone walls, floor surfaces and drains in the area of the Kilmainham Sheds. To the south of the proposed development site, a sluice gate forming part of the canal architecture was also exposed, recorded and preserved in situ.

A watercourse depicted on the 1:1056 map of 1864 was uncovered in Trenches 56, 57 and 58. The north-east/south-west orientated section of this watercourse, as exposed in Trenches 56 and 57, was a U-shaped ditch that measured a maximum of 3m in width at the top and 2m in depth. Fifteen post-holes cut into the underlying natural (F72) were also uncovered across the site in Areas 3, 5 and 8 and may represent the remains of timber buildings depicted on the OSI 1:1056 maps of 1864 and 1887. Sections of brick and stone walls were also exposed across the proposed development area, reflecting the long building history of the site. Many of these are depicted on the various known mapping that span the mid-nineteenth to the mid-twentieth century.
East of the southern end of the proposed development site a sluice gate was exposed, recorded and preserved in situ. The position of the gate suggests that it was used to control the flow of water between a reservoir to the north and the canal to the south. The wooden gate, preserved as horizontal and vertical planks with iron bracing, had an arched opening to the rear and was set in vertical grooves cut into two opposing, stepped walls of dressed limestone.

All 19th- and 20th-century features uncovered within the test trenches were excavated and the ground was exposed to natural deposits. Subsequent to this phase of test trenching, all ground reduction was monitored by Archaeological Management Solutions (AMS), therefore no additional archaeological assessment is required.